南四湖浮游动物群落结构特征及其与环境因子的关系

为探讨南四湖浮游动物多样性特征及其与水质的相关性,于2012年夏季(7月)和冬季(12月)对南四湖浮游动物的群落结构进行了系统研究,结合历史数据,分析了南四湖浮游动物群落的多样性特征和时间变化。共采集到浮游动物163种,其中,轮虫78种,原生动物65种,枝角类17种,桡足类3种。夏季记录浮游动物种类数(141种)高于冬季(105种)。从四个湖区来看,微山湖浮游动物种数最多(102种),其次是南阳湖(95种)和昭阳湖(80种),独山湖(73种)较少。南四湖浮游动物全年平均密度为2 192 ind/L,平均生物量为2.27 mg/L。除原生动物外,其他三类浮游动物夏季的平均密度和生物量都高于冬季。采用丰富度指数、Shannon-Wiener指数和均匀度指数对浮游动物多样性进行了评价,结果均显示,南四湖浮游动物多样性夏季高于冬季。通过回归分析发现,总氮是影响浮游动物密度的主要因素,总氮和水温是影响浮游动物生物量的主要因素,p H和电导率是影响浮游动物多样性的主要因素。

Assessment of Characteristics of Zooplankton Community and the Association with Water Quality in Nasi Lake

In order to evaluate the characteristics of zooplankton community in Nansi Lake and the relationship between the zooplankton community and the water quality, samples were collected in July (summer) and December (winter), 2012, from Nansi Lake. Combined with historical data, the characteristics of zooplankton community in Nansi Lake and the temporal and spatial variation were described. Environmental factors of each sample site were also collected and regression analysis of the zooplankton community diversity and environmental factors was carried out. As a result, 163 zooplankton species were identified, including 78 Rotifera, 65 Protozoa, 17 Cladocera and 3 Copepoda. 141 zooplankton species were identified in summer, and 105 species were found in winter. Most of zooplankton species were found in the Weishan Lake, followed by Nanyang Lake, Zhaoyang Lake and Dushan Lake. The average density of zooplankton species in Nansi Lake is 2192 ind/L, and the average biomass is 2.27 mg/L. Most of the zooplankton species have higher density and biomass in summer than in winter except the Protozoa. The richness indexes, Shannon-Wiener indexes and evenness indexes in summer and winter of zooplankton community in Nansi Lake are 3.52 and 2.52,3.96 and 3.48,0.57 and 0.52, respectively. Stepwise regression analysis on the density, mass and diversity indexes with the environmental indexes indicated that, total nitrogen is the most important index affect on zooplankton density, total nitrogen and water temperature are most important indexes affect on zooplankton mass, and pH and conductivity are most important indexes affect on zooplankton diversity.